Theoretical explorations of enantioselective alkylation reactions of pyrroles and indoles organocatalyzed by chiral imidazolidinones

The transition structures for MacMillan's alkylations of N-methylpyrrole by aldehydes catalyzed by chiral amine salts were explored with B3LYP/6-31G(d) density functional theory. These results provide an explanation of the enantioselectivities observed with these two catalysts.